Composite pipe for nuclear fuel component and manufacturing method of composite pipe

Abstract

The invention discloses a composite pipe for a nuclear fuel component and a manufacturing method of the composite pipe. The composite pipe for the nuclear fuel component comprises an inner pipe and anouter pipe which is tightly matched with the periphery of the inner pipe; the inner pipe is a ceramic pipe formed by weaving ceramic fibers or a metal pipe; and the outer pipe is a ceramic pipe or ametal pipe formed by sintering. By adopting the composite pipe and the manufacturing method, the structure and the preparation technology of a multi-layer ceramic composite pipe are simplified; a zircaloy cladding is avoided from generating rapid reaction with a coolant to produce a great quantity of hydrogen to cause hydrogen decrepitation under the accident working condition; the high-temperature intensity of a cladding material is improved, so that the cladding material can still keep self shape under the accident working condition without generating failure, and a coolant flow passage is clear; the high-temperature mechanical performance of the cladding material is improved, the temperature of the coolant of a reactor core under the normal running working condition can be increased, the output power of a reactor and the heat efficiency are improved, and higher economy is brought; and a safety system of the existing reactor is hopefully simplified, and the reliability and the economy of the composite pipe are improved.

Description

technical field

[0001] The invention relates to the technical field of nuclear fuel, in particular to a composite pipe for a nuclear fuel assembly and a manufacturing method thereof. Background technique

[0002] Zirconium alloys are widely used as cladding tube materials for existing pressurized water reactor nuclear power plants due to their very low thermal neutron absorption cross section, good high temperature water corrosion resistance and mechanical properties.

[0003] In the Fukushima nuclear accident in Japan on March 11, 2011, radioactive substances were released due to the melting of the fuel, and the zirconium alloy used as the fuel cladding tube reacted with water to cause a hydrogen explosion, which eventually led to the catastrophic consequences of large-scale diffusion of radioactive substances . Fukushima accident brings awareness to existing UO 2 The -Zr fuel system presents serious risks under severe accident conditions. After the Fukushima nuclear acc...

Examples

Embodiment 1

[0047] Inner tube: The third-generation SiC fiber with a high stoichiometric ratio is woven into an elastic inner tube skeleton with a wall thickness of 0.2mm, an outer diameter of 9.4mm, and a length of 800mm. Using the precursor impregnation pyrolysis process (PIP), the low-melting polycarbosilane is used as a precursor to infiltrate the inner tube skeleton of the fiber braid, and it is cracked at a low temperature under normal pressure, so that the precursor and the fiber undergo a cross-linking reaction to form a dense elastic inner tube (Ceramic tube).

[0048]Outer tube: High-purity SiC powder is used to prepare thin-walled tube blanks, which are pressed into green bodies with high strength and density by cold isostatic pressing, and sintered at high temperature under normal pressure to obtain a density of 3.1g / cm 3 A dense SiC ceramic tube with an outer diameter of 10mm, a wall thickness of 0.7mm, and a length of 800mm.

[0049] The inner tube is compressed so that it ...

Embodiment 2

[0051] Inner tube: Use metal tantalum with good formability and elasticity to make an elastic inner tube (tantalum tube) with a wall thickness of 0.2mm, an outer diameter of 9.4mm, and a length of 800mm by multiple cold rolling-heat treatment methods. Surface induction heating is carried out on the tantalum tube, and pre-oxidation treatment is carried out.

[0052] Outer tube: High-purity SiC powder is used to prepare thin-walled tube blanks, which are pressed into green bodies with high strength and density by cold isostatic pressing, and sintered at high temperature under normal pressure to obtain a density of 3.1g / cm 3 Above, a dense SiC ceramic tube with an outer diameter of 10mm, a wall thickness of 0.7mm, and a length of 800mm.

[0053] The inner tube is compressed to fit into the outer tube, and the tantalum tube is expanded by water pressure or air pressure, and is tightly combined with the inner wall of the outer SiC ceramic tube to obtain a composite tube.

Embodiment 3

[0055] Inner tube blank: using NS-Mo powder in a cold isostatic press with a pressure of 120MPa to obtain a relatively high-density tube blank with an outer diameter of 59.5mm and a suitable inner diameter.

[0056] Outer tube blank: ODS-FeCrAl powder is used to obtain a relatively dense tube blank with an outer diameter of 66mm and an inner diameter of 60mm in a cold isostatic press at a pressure of 120MPa.

[0057] Double-layer composite pipe: put the inner pipe blank into the outer pipe blank, and then perform hot isostatic pressing at 1000°C with a pressure of 200MPa, and finally obtain a high-density double-layer composite metal pipe blank. Through multiple hot rolling, cold rolling and intermediate heat treatment, a reasonable amount of wall reduction and diameter reduction is adjusted, and finally a long tube (composite tube) with an outer diameter of 9.5mm, a wall thickness of 0.4mm, and a length of 4m is obtained. Among them, the ODS-FeCrAl outer tube wall thickness i...

technical field

[0001] The invention relates to the technical field of nuclear fuel, in particular to a composite pipe for a nuclear fuel assembly and a manufacturing method thereof. Background technique

[0002] Zirconium alloys are widely used as cladding tube materials for existing pressurized water reactor nuclear power plants due to their very low thermal neutron absorption cross section, good high temperature water corrosion resistance and mechanical properties.

[0003] In the Fukushima nuclear accident in Japan on March 11, 2011, radioactive substances were released due to the melting of the fuel, and the zirconium alloy used as the fuel cladding tube reacted with water to cause a hydrogen explosion, which eventually led to the catastrophic consequences of large-scale diffusion of radioactive substances . Fukushima accident brings awareness to existing UO 2 The -Zr fuel system presents serious risks under severe accident conditions. After the Fukushima nuclear acc...

Examples

Embodiment 1

[0047] Inner tube: The third-generation SiC fiber with a high stoichiometric ratio is woven into an elastic inner tube skeleton with a wall thickness of 0.2mm, an outer diameter of 9.4mm, and a length of 800mm. Using the precursor impregnation pyrolysis process (PIP), the low-melting polycarbosilane is used as a precursor to infiltrate the inner tube skeleton of the fiber braid, and it is cracked at a low temperature under normal pressure, so that the precursor and the fiber undergo a cross-linking reaction to form a dense elastic inner tube (Ceramic tube).

[0048]Outer tube: High-purity SiC powder is used to prepare thin-walled tube blanks, which are pressed into green bodies with high strength and density by cold isostatic pressing, and sintered at high temperature under normal pressure to obtain a density of 3.1g / cm 3 A dense SiC ceramic tube with an outer diameter of 10mm, a wall thickness of 0.7mm, and a length of 800mm.

[0049] The inner tube is compressed so that it ...

Embodiment 2

[0051] Inner tube: Use metal tantalum with good formability and elasticity to make an elastic inner tube (tantalum tube) with a wall thickness of 0.2mm, an outer diameter of 9.4mm, and a length of 800mm by multiple cold rolling-heat treatment methods. Surface induction heating is carried out on the tantalum tube, and pre-oxidation treatment is carried out.

[0052] Outer tube: High-purity SiC powder is used to prepare thin-walled tube blanks, which are pressed into green bodies with high strength and density by cold isostatic pressing, and sintered at high temperature under normal pressure to obtain a density of 3.1g / cm 3 Above, a dense SiC ceramic tube with an outer diameter of 10mm, a wall thickness of 0.7mm, and a length of 800mm.

[0053] The inner tube is compressed to fit into the outer tube, and the tantalum tube is expanded by water pressure or air pressure, and is tightly combined with the inner wall of the outer SiC ceramic tube to obtain a composite tube.

Embodiment 3

[0055] Inner tube blank: using NS-Mo powder in a cold isostatic press with a pressure of 120MPa to obtain a relatively high-density tube blank with an outer diameter of 59.5mm and a suitable inner diameter.

[0056] Outer tube blank: ODS-FeCrAl powder is used to obtain a relatively dense tube blank with an outer diameter of 66mm and an inner diameter of 60mm in a cold isostatic press at a pressure of 120MPa.

[0057] Double-layer composite pipe: put the inner pipe blank into the outer pipe blank, and then perform hot isostatic pressing at 1000°C with a pressure of 200MPa, and finally obtain a high-density double-layer composite metal pipe blank. Through multiple hot rolling, cold rolling and intermediate heat treatment, a reasonable amount of wall reduction and diameter reduction is adjusted, and finally a long tube (composite tube) with an outer diameter of 9.5mm, a wall thickness of 0.4mm, and a length of 4m is obtained. Among them, the ODS-FeCrAl outer tube wall thickness i...

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